Hitherto, a stereoscopic image display apparatus as shown in FIG. 1 is proposed as a stereoscopic image generation apparatus which enables the operator to appreciate stereoscopic images.
The stereoscopic image display apparatus 1 is constructed so as to project left-eye projecting light and right-eye projecting light from a left-eye projector 2L and a right-eye projector 2R through each read, green, and blue three primary color polarized filters 3LR, 3LG, 3LB, and 3RR, 3RG, 3RB on a screen 4 to display color composite image on the screen 4, so that the operator can see the color composite image through glasses 5 having a left-eye filter 5L and a right-eye filter 5R.
In this case, the operator sees the left-eye image out of the color composite image projected from the left-eye projector 2L through the left-eye filter 5L, and also sees the right-eye image projected from the right-eye projector 2R through the right-eye filter 5R. As a result, as shown in FIGS. 2(A) to 2(C), the operator perceives the color composite image on the screen 4 as a stereoscopic image based on visual difference between a left eye 6L and a right eye 6R.
Incidentally, as shown in FIG. 2(A), when a left-eye image 7L projected from the left-eye projector 2L and a right-eye image 7R projected from the right-eye projector 2R are displayed on the same position on the screen 4, 8L, the operator's left eye 6L, is crossed with 8R, the operator's right eye 6R, at the same point on the screen 4, so that the operator recognizes as if "there is a composite stereoscopic image on the screen 4."
On the contrary, as shown in FIG. 2(B), when the left-eye image 7L and the right-eye image 7R are displayed shifting with each other at the position opposite to the left eye 6L and the right eye 6R on the screen 4, a virtual image 9B is imaged at the point in the virtual space (it is generated backward than the screen 4) in which the operator's eye BL seeing the left-eye image 7L by the his/her left eye 6L and the operator's eye 8R seeing the right-eye image 7R by the his/her right eye 6R are crossed. This makes the operator to recognize as if "there is a composite stereoscopic image backward the screen 4."
Further, as shown in FIG. 2(C), when the right-eye image 7R and the left-eye image 7L are projected at the position on the screen 4 opposite to the left eye 6L and the right eye 6R, the operator's eye 8L seeing the left-eye image 7L by the left eye 6L and the operator's eye 8R seeing the right-eye image 7R by the right eye 6R are crossed at the forward position than the screen 4 in the virtual space, and a virtual image 9F is imaged. This makes the operator recognize as if "there is a composite stereoscopic image in front of the screen 4."
Consequently, since the projecting points of the left-eye image 7L and the right-eye image 7R on the screen 4 can be shifted by the distance corresponding to the visual difference between the left eye 6L and the right eye 6R, the operator can appreciate the composite stereoscopic image as if it were displayed at the position of the screen 4, or backward or front in the screen 4.
When generating a stereoscopic image by way of such method, however, it is very difficult actually to decide the projecting positions of the left-eye image 7L and the right-eye image 7R projected from the left-eye projector 2L and the right-eye projector 2R, which requires the operator well enough skill.
Incidentally, visual difference between the left eye 6L and the right eye 6R is actually not so large (3.25 cm! and the like), so that actual generation of effective stereoscopic image requires the complicated setting operation that the skilled operator sets the projecting point of the left-eye image 7L and the right-eye image 7R by changing with trials and errors.